The first thing is to go look at some RV's and then pick a type. Travel trailer, fifth wheel, class a, class c or class b.
Then come back and people can help you a little better.
The cheapest entry is probably a Travel trailer and a truck. You can find a ton of different floor plans that will fit any lifestyle. Some manufacturers frown on you living in them full time. So keep that in mind. Grand Design, artic fox and I'm sure there are more don't care.
Don't skimp on size, you'll want to be comfortable. Go check out floor plans, pretend to live in them and see how they feel.
2019 Grand Design Momentum 395
2018 Ram 3500 DRW 4.10
2014.5 DRV Atlanta (sold)
2008 Newmar 4330 (Modified) Sold